Iodine synthetic applications

The synthetic applications of this reagent to the synthesis of nitroalkenes have been known since the 1960s.60 Nitration of alkenes with nitryl iodide, generated in situ from iodine and silver nitrite, is convenient for the synthesis of P-nitrostyrenes with various functional groups.61 This method is applied to the synthesis of ortho-methoxylated phenylisopropylamines, which are potent serotonine agonists (Eq. 2.31).62... 

The purpose of this book is to address and summarize recent developments and synthetic applications in the field of hypervalent iodine chemistry. Therefore, emphasis is placed on the post 1990s literature with reference to earlier work where necessary and appropriate. 

Aryl-, as well as heteroaryliodonium salts, belong to the most common, stable, and well investigated class of polyvalent iodine compounds. The preparation and chemistry of aryliodonium salts was extensively covered in several reviews [5,7,9,10]. Diaryliodonium salts have found synthetic application as arylating reagents in reactions with various organic substrates. 

It can be anticipated that these areas of synthetic application will continue to attract significant research activity in the future. The increasing use of the transition metal-mediated coupling reactions of iodonium salts may add a new dimension to the field of polyvalent iodine chemistry. 

The powerful oxidizing character of iodine(V) is not amply manifested in iodylarenes, the synthetic applications of which are limited. This is partly due to their polymeric nature which makes them insoluble in most ordinary solvents, with the exception of water. Nevertheless, iodylbenzene and also 3-iodylbenzoic acid in the presence of catalytic amounts of other reagents can be of considerable synthetic utility. 

H. Tohma and Y. Kita, Synthetic Applications (total synthesis and natural product synthesis), in Hypervalent Iodine Chemistry Modem Developments in Organic Synthesis Top. Curr. Chem., 2002, 224, 209. 

The oximes of unsaturated carbonyl compounds react with alkenes in the presence of electrophiles to give nitrones. By contrast, the acetaldehyde oxime and iodine added to cyclohexene to give 8 in low yield as a single diastereomer, although no synthetic application of the reaction has been reported174... 

Wirth, T., Hirt, U. H. Hypervalent iodine compounds. Recent advances in synthetic applications. Synf/res/s 1999,1271-1287. 

Hypervalent Iodine Chemistry Preparation, Structure and Synthetic Applications of Polyvalent Iodine Compounds, First Edition. Viktor V. Zhdankin. 2014 John Wiley Sons, Ltd. Published 2014 by John Wiley Sons, Ltd. 

Hypervalent iodine(III) compounds, such as [bis(trifluoroacetoxy)iodo]benzene, (diacetoxyiodo)benzene and [hydroxy(tosyloxy)iodo]benzene, are commonly used as reagents in various cationic cyclizations, rearrangements and fragmentations. Numerous examples of such reactions have been reported in the literature and summarized in the reviews dedicated to synthetic applications of hypervalent iodine compounds [4,7,10,11, 180, 191, 387]. 

Additional examples of synthetic applications of hypervalent iodine-induced heterocyclizations include the following the metal-free one-pot synthesis of 2-acylbenzothiazoles by oxidative cyclization of multiform substrates [434], iodine(III)-mediated tandem oxidative cyclization for construction of 2-nitrobenzo[ ]furans [435], hypervalent iodine mediated oxidative cyclization of o-hydroxystilbenes into benzo- and naphthofu-rans [436], PhI(OCOCF3)2-mediated synthesis of 3-hydroxy-2-oxindoles and spirooxindoles from anilides [437], synthesis of isoxazoles by hypervalent iodine-induced cycloaddition of nitrile oxides to alkynes [438],... 

Iodine pentafluoride, IF5, has found some synthetic application as a powerful fluorinating reagent [1311, 1312]. For example, IF5, in combination with pyridine and HF, can be used as a fluorination reagent for the introduction of fluorine atoms to the a-position in sulfldes (Scheme 3.365) [1313]. A similar fluorination of sulfldes using IF5 without pyridine and HF affords a mixture of polyfluorinated products [1314]. 

Additional examples of synthetic application of periodic acid as an oxidant include the oxidative iodination of aromatic compounds [1336-1341], iodohydrin formation by treatment of alkenes with periodic acid and sodium bisulfate [1342], oxidative cleavage of protecting groups (e.g., cyclic acetals, oxathioacetals and dithioacetals) [1315, 1343], conversion of ketone and aldehyde oximes into the corresponding carbonyl compounds [1344], oxidative cleavage of tetrahydrofuran-substituted alcohols to -y-lactones in the presence of catalytic PCC [1345] and direct synthesis of nitriles from alcohols or aldehydes using HsIOe/KI in aqueous ammonia [1346],... 

The oxidation of phenols or o- and p-hydroquinones with stoichiometric [bis(acyloxy)iodo]arenes to the corresponding benzoquinones is one of the most typical synthetic applications of hypervalent iodine reagents (Section 3.1.11). The catalytic version of this reaction was first reported by Yakuraand Konishi in 2007 [52], The reaction of p-alkoxyphenols 50 with a catalytic amount of 4-iodophenoxyacetic acid in the presence of Oxone as the terminal oxidant in aqueous acetonitrile at room temperature affords p-quinones 51 in high yields (Scheme 4.26) [52]. 4-Iodophenoxyacetic acid is a readily available and water-soluble aromatic iodide that has a particularly high catalytic activity in this reaction. 

Hypervalent iodine(V) reagents, such as IBX (2-iodoxybenzoic acid) and DMP, have found widespread synthetic application as stoichiometric oxidants for the facile and selective oxidation of primary alcohols and secondary alcohols to the respective carbonyl compounds and for other important oxidative transformations... 

Preparation, Structure and Synthetic Applications of Polyvalent Iodine Compounds... 

Despite the demonstrated success of NBS and the hypervalent iodine compounds as modem HR reagents, the classical variant lead tetraacetate continues to find synthetic applications. A synthesis of the carbocyclic nucleoside (-)-aristeromycin features the conversion of amide 122 to Boc-protected amine 123. Similar tactics are used for syntheses of 6 - 3-... 

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